The present invention relates to a disc reproduction device for a disc such as a CD (compact disc) and a DVD (digital versatile disc), more specifically, to a disc reproduction device of a carrousel type that can hold a plurality of discs.
Among the disc reproduction devices for the CD, the DVD and the like, aside from a reproduction device that holds and reproduces one disc, there exists a so-called disc changer that holds a plurality of discs at once and optionally selects one of them for reproduction. The disc changer has two types. One is a magazine type (also referred to as a cartridge type) where the discs are stacked in a box-shaped magazine. Another one is a carrousel type as shown in FIG. 1 where a plurality of discs (normally three to five discs) D1 to D5 (shaded areas) is placed flatways on disc mounting portions around a central shaft O at even intervals. The disc mounting portions are on a circular large tray 31 which rotates around the central shaft O on a table 30 of a drawer type as shown in the plan view of FIG. 1. The rotation of the tray 31 is controlled in order to move a desired disc to a reproduction unit 32 to reproduce the disc.
Since the above-described disc reproduction device of the carrousel type can selectively move the desired disc from the plurality of discs D1 to D5 to the position of the reproduction unit 32 only by controlling the rotation of the large tray 31, it has an advantage that a mechanical structure and control can be simpler than the disc reproduction device of the magazine type that requires a mechanism for selectively taking out a disc from the magazine.
However, the above-described large tray 31 needs an area where the plurality of discs D1, D2, D3 and so on, such as three or five discs, can be placed flatways around the central shaft O. Diameter of the large tray increases as the number of the discs thereof increases, and a width dimension and a depth dimension of the disc reproduction device become larger accordingly. For example, in the case of the CD or the DVD, the disc diameter is 12 cm. Thus, the diameter of the tray 31 for holding five discs as shown in FIG. 1 needs to be about 32 cm, which may be a limit of allowable maximum dimensions for a disc reproduction device for public use.
As a matter of course, it is preferable that a disc reproduction device can hold a large number of discs; therefore, it is required that as many discs as possible are held in the allowable dimensions.
Therefore, in the carrousel type disc reproduction device, an attempt has been proposed in which width and depth dimensions of the disc reproduction device are reduced by making a diameter of a tray small through making portions of a plurality of adjacent discs overlap with each other. On a tray 35 disclosed in Japanese Patent Publication No. 2729878 shown in the plan view of FIG. 2, three disc mounting portions 36a, 36b and 36c (concave portions that fit the dimensions of the discs D1 to D3) are arranged around the central shaft O at even intervals (interval of 120xc2x0) so as to overlap with each other (note that a clamping area K of each disc held is designed not to overlap). Thus, the diameter of the tray 35 is made to be smaller than the diameter of the trays where the discs are arranged without overlapping.
However, in the tray 35 of FIG. 2, since portions of all discs overlap with adjacent discs, exchange of the discs is considerably difficult, and there is a problem that the discs are easily scratched.
Since the discs remain overlapped in a reproduction state, there is little clearance with a reproduction unit, which is not mechanically safe and sure.
Therefore, the followings are required for the disc reproduction device of the carrousel type.
(1) As many discs as possible can be held.
(2) The width and depth dimensions of the device for installation, in other words, the diameter of the tray where the plurality of discs are mounted should be as small as possible.
(3) Exchange of the discs should be easy. In other words, the area above the disc at a disc exchange position should be open.
(4) The disc at a position for a reproduction state should not be overlapped with other discs both at the upper and lower portions.
The present invention has been created in consideration of the above-described circumstances. Accordingly, it is an object of the present invention to provide a disc reproduction device of a carrousel type that satisfies the foregoing requirements (1) to (4).
The present invention provides the followings to solve the above-described problems.
(1) A disc reproduction device 20 that comprises:
a plurality of disc mounting portions arranged around a central shaft O, which holds discs D1 to D7 and is rotatively moved by a rotation drive mechanism; and a reproduction unit 32, where the plurality of disc mounting portions are rotatively moved around the central shaft O one stroke by one stroke, the one stroke being a movement of the disc mounting portion to a position of an adjacent disc mounting portion, and the reproduction unit 32 is set to reproduce the disc D1 held in the disc mounting portion positioned on the reproduction unit 32,
in which the disc mounting portions include: independent trays 1 to 7 (a first tray to a seventh tray) divided for each disc; and driver for moving each of the trays 1 to 7 horizontally or upward/downward obliquely in a parallel manner around the central shaft O with every stroke of movement such that each of the trays 1 to 7 is at a bottom stage (PP) when being at a reproduction position which is on the reproduction unit 32 and is not overlapping with other trays, is at a top stage when being at a disc exchange position (EP), and is at a middle stage (WP) or the bottom stage (PP) during other standby state and a portion of each of the trays overlaps with an adjacent tray.
(2) The disc reproduction device 20 according to the foregoing (1), that comprises:
an inner gear 16 formed on the inner circumference side of each of the trays 1 to 7 each having a fan-shaped form with identical shape and dimensions, which engages with a gear 17 or a gear 18 of a drive source;
a protruding portion 14 projecting downward from a center of a lower surface of the inner circumference side of each of the trays; and
a convex portion 15 for regulating a rotation path, horizontally protruding toward the outer circumference side and the inner circumference side of each of the trays, which is provided as the driver for moving each of the trays horizontally or upward/downward obliquely in the parallel manner around the central shaft O,
in which the inner gear 16 of the tray positioned at the top stage (EP) and the bottom stage (PP) is engaged with the gear 17 or the gear 18 of the drive source severally arranged at specified positions and is driven, and
other trays that are not directly driven include: an interlocking mechanism where the adjacent tray abuts and moves a side surface or the protruding portion 14 of the tray; and a sliding mechanism where each tray rotates around the central shaft O while the convex portion 15 is supported on orbits R1 and R2 to maintain a horizontal state.
(3) The disc reproduction device 20 according to the foregoing (1) or (2), in which the tray positioned at the middle stage (WP) in the beginning of the movement of one stroke and the tray to be moved to the middle stage (WP) comprise driver for providing the trays thereof a period of time in which the trays are still within a moving time of one stroke.